You nothing need to change any port.
The installer will do automatically, You just need to install as per provided method.
The issue is with your setting.
How site will work when script using port 8081 and you have set 8081?

Just uninstall and reinstall and don’t change any port.
The Apache port should be 80 before install.

The Nginx Admin v1.4 is almost same as Nginx Admin 1.3.
We only release Nginx Admin v1.4 for those who want to use in cPanel 11.28.
There is no much differance in v1.3 and v1.4, The only differance is cPanel 11.28 compatibality.

The latest 1.4 release of NginxCP has a small bug in the installer file where you check the version. It checks if you have 11.28 and then prompts to upgrade to 11.25. So you should probably want to change the messages there.

Additionally, I’ve taken the time and improved the page within WHM/cPanel, to make it more user friendly and added a couple of things. Here is the screenshot I uploaded recently:

If you want to add the code (it’s just the addon_nginx.cgi, nginx.php and 1 image file), just contact me back.

The Latest Nginx Admin Installer prompts “Upgrade to 11.25 or later”
Good to see your improved interface. We always welcome to all develpers in Nginx Admin Project.
Please send me in zip format via email at 9xlinux@live.com so I can check and release in next update.

Hi,
during reboot, when httpd service is starting I get the following error messages. Everything is working fine, but this error happens for every domain on the server, just curious how to fix it.
*******
Starting httpd: Starting nginx daemon: nginx[warn]: conflicting server name “173.208.123.38” on 173.208.123.38:80, ignored
[warn]: conflicting server name “173.208.123.38” on 173.208.123.38:80, ignored